lkml.org 
[lkml]   [2023]   [Jan]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
Subject[PATCH 13/41] mm: introduce vma->vm_flags modifier functions
From
To keep vma locking correctness when vm_flags are modified, add modifier
functions to be used whenever flags are updated.

Signed-off-by: Suren Baghdasaryan <surenb@google.com>
---
include/linux/mm.h | 38 ++++++++++++++++++++++++++++++++++++++
include/linux/mm_types.h | 8 +++++++-
2 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index ec2c4c227d51..35cf0a6cbcc2 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -702,6 +702,44 @@ static inline void vma_init(struct vm_area_struct *vma, struct mm_struct *mm)
vma_init_lock(vma);
}

+/* Use when VMA is not part of the VMA tree and needs no locking */
+static inline
+void init_vm_flags(struct vm_area_struct *vma, unsigned long flags)
+{
+ WRITE_ONCE(vma->vm_flags, flags);
+}
+
+/* Use when VMA is part of the VMA tree and needs appropriate locking */
+static inline
+void reset_vm_flags(struct vm_area_struct *vma, unsigned long flags)
+{
+ vma_write_lock(vma);
+ init_vm_flags(vma, flags);
+}
+
+static inline
+void set_vm_flags(struct vm_area_struct *vma, unsigned long flags)
+{
+ vma_write_lock(vma);
+ vma->vm_flags |= flags;
+}
+
+static inline
+void clear_vm_flags(struct vm_area_struct *vma, unsigned long flags)
+{
+ vma_write_lock(vma);
+ vma->vm_flags &= ~flags;
+}
+
+static inline
+void mod_vm_flags(struct vm_area_struct *vma,
+ unsigned long set, unsigned long clear)
+{
+ vma_write_lock(vma);
+ vma->vm_flags |= set;
+ vma->vm_flags &= ~clear;
+}
+
static inline void vma_set_anonymous(struct vm_area_struct *vma)
{
vma->vm_ops = NULL;
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 5f7c5ca89931..0d27edd3e63a 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -553,7 +553,13 @@ struct vm_area_struct {
* See vmf_insert_mixed_prot() for discussion.
*/
pgprot_t vm_page_prot;
- unsigned long vm_flags; /* Flags, see mm.h. */
+
+ /*
+ * Flags, see mm.h.
+ * WARNING! Do not modify directly to keep correct VMA locking.
+ * Use {init|reset|set|clear|mod}_vm_flags() functions instead.
+ */
+ unsigned long vm_flags;

#ifdef CONFIG_PER_VMA_LOCK
int vm_lock_seq;
--
2.39.0
\
 
 \ /
  Last update: 2023-03-26 23:33    [W:0.723 / U:0.064 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site